1. Field of the Invention
The present invention relates to a fan module and, more particularly, to a fan module that can draw air into the fan in different directions.
2. Description of the Related Art
Conventional cooling fans generally include axial-flow types and blower types. Axial-flow type cooling fans include an axial air inlet and an axial air outlet spaced from the axial air inlet in an axial direction. Air can be drawn in via the axial air inlet and exit via the axial air outlet to provide a cooling effect. Blower type cooling fans include an axial air inlet in an axial direction and a radial air outlet in a radial direction. Air can be drawn in via the axial air inlet and exit via the radial air outlet to provide a cooling effect.
Generally, conventional cooling fans of both the axial-flow type and the blower type can be used in various electronic products to prolong the service lives of the electronic products by providing heat dissipation. However, these conventional cooling fans of both the axial-flow type and the blower type can not fulfill the cooling need in small-size electronic products, such as notebook computers, mobile phones, and personal digital assistants, having a developing trend of miniaturization and having higher operating speeds.
In view of the above disadvantage, Taiwan Utility Model Publication No. 515939 entitled “HEAT DISSIPATING MODULES” discloses a fan module for notebook computers. With reference to FIG. 1, the fan module 8 disclosed in this patent includes a fan 81 and a heat dissipater 82. The fan 81 is mounted in a notebook computer 83 for creating air currents. The heat dissipater 82 is mounted in an air outlet of the fan 81 and engaged with chips 831 of the notebook computer 83. Thus, the fan 81 provides the chips 831 with a predetermined cooling effect.
In use, the fan 81 can only draw external air into the fan module 8 for dissipating heat in a certain portion (such as the chips 831) of the notebook computer 83. The fan 81 can not draw air in other directions into the fan module 8, failing to expel hot air currents generated by the other electronic components of the notebook computer 83 and, thus, providing limited cooling effect for the notebook computer 83.
FIG. 2 shows Taiwan Invention Publication No. I264500 entitled “BLOWER TYPE HEAT DISSIPATING FAN WITH INCREASED AIR INPUT”. The cooling fan 9 disclosed in this patent includes a housing 91, a main impeller 92, and an auxiliary impeller 93. The housing 91 includes an air inlet 911 and an air outlet 912. The main impeller 92 is a blower type impeller mounted in the housing 91. The auxiliary impeller 93 is an axial-flow type impeller mounted in the air inlet 911. When the auxiliary impeller 93 rotates, the amount of air inputted via the air inlet 911 can be increased. The main impeller 92 can output the air currents in a sideward direction, increasing the overall cooling effect.
Although the amount of input air of the cooling fan 9 can be increased by the auxiliary impeller 93, the cooling fan 9 can only draw air in the axial direction into the housing 91 and, thus, has the same disadvantage of failing to draw air in other directions when the cooling fan 9 is used in a notebook computer 83 or the like.
Thus, a need exits for a novel fan module that can draw air into the fan in different directions.